A heat insulating box such as a refrigerator having a plurality of rooms is provided with a partition plate that is a resin molded article including a heat insulating material inside thereof so that it is partitioned into rooms having different environments such as a temperature and a humidity depending on contents of stored food or the like.
The strength of the refrigerator is improved by the partition plate being mounted. In particular, a design plate located on an opening side of the box includes a design surface and an end side bent at a right angle to the design surface to form a substantially U-shaped cross section, and its end side is placed under an outer shell surface layer of the partition plate to be fixed in such a manner that the end side is covered. With this configuration, the strength of the heat insulating box is improved.
Further, since packing provided on a door and the box are held in a sealed state, the design plate is required to be adsorbed by a magnet provided inside the packing. At the same time, since the influence on strength improvement of the refrigerator is large, a low-priced coated steel plate of high strength is used for the design plate.
However, the design plate includes a portion exposed to the outside of the room and is made of a steel plate excellent in thermal conduction. Accordingly, a heat flow from a high temperature zone outside the room to a low temperature zone inside the room is generated on the end side of the design plate disposed near the outer shell surface of the partition plate. As a result, heat insulating performance of the heat insulating box decreases, and the temperature of the design plate itself drops to a dew point of the outside air (installation atmosphere of refrigerator) or lower, thereby causing dew condensation.
In response to such a problem, in PTL 1, an attempt to suppress occurrence of dew condensation is made. FIGS. 19 and 20 are views illustrating a structure of a conventional refrigerator and a structure of a peripheral region of a partition plate and a design plate with respect to the conventional refrigerator disclosed in PTL 1, respectively.
FIG. 19 is a view illustrating whole conventional refrigerator 200, and illustration of a door is omitted for simplicity. Refrigerator 200 includes inner box 4 made of plastic and outer box 5 made of metal in a combined state, and includes a plurality of storage rooms such as first storage room 2 and second storage room 3. Each storage room is partitioned by partition plate 1 made of plastic and design plate 11 made of metal mounted on a front face of the refrigerator.
FIG. 20 is a view illustrating a cross section of portion α in FIG. 19 in detail, which illustrates partition plate 1 between first storage room 2 and second storage room 3 and design plate 11. Partition plate 1 is configured by disposing upper plate 6 and lower plate 7 on upper and lower sides of foamed urethane heat insulating material 8 enclosed from the back surface of the refrigerator, respectively. Further, heat radiation pipe 10 for heat radiation of a refrigerating cycle is disposed on foamed urethane heat insulating material 8 and the front surface thereof between upper plate 6 and lower plate 7. Heat radiation pipe 10 is in contact with design plate 11 via heat storage layer 18. Solid foamed flexible heat insulating material 9 including an expanded polystyrene and the like, which is provided to suppress urethane leakage to the front surface of the refrigerator, is pressed by design plate 11 when foamed urethane heat insulating material 8 is enclosed from the back surface of the refrigerator. With such a temperature raising mechanism, heat generated in heat radiation pipe 10 is transmitted to design plate 11 and a peripheral region such as gasket 17 of door 16, and the temperature of design plate 11 and the peripheral region such as gasket 17 is raised to the dew point or higher, thereby suppressing occurrence of dew condensation.
The temperature raising mechanism is compatible with the heat radiation of the refrigerating cycle and dew condensation suppression at the peripheral region of the design plate, and is a highly efficient energy saving mechanism. However, in the mechanism described above, heat radiation pipe 10, heat storage layer 18, design plate 11, and upper plate 6 or lower plate 7 of partition plate 1 are placed in contact with one another, whereby the heat generated in heat radiation pipe 10 tends to intrude into the storage room through path A illustrated in FIG. 20. Energy saving performance of the refrigerator is greatly impaired when the heat of heat radiation pipe 10 having a temperature higher than the room temperature intrudes into the storage room.
In order to avoid such a problem, there is a structure disclosed in PTL 2. FIGS. 21 and 22 are views illustrating a structure of a conventional refrigerator and a structure of a peripheral region of a partition plate and a design plate with respect to the conventional refrigerator disclosed in PTL 2, respectively. FIG. 21 is a view illustrating whole conventional refrigerator 300, and illustration of a door is omitted for simplicity. Refrigerator 300 includes inner box 4 made of plastic and outer box 5 made of metal in a combined state, and includes a plurality of storage rooms such as first storage room 2 and second storage room 3. Each storage room is partitioned by partition plate 301 made of plastic and design plate 11 made of metal mounted on a front face of the refrigerator.
FIG. 22 is a view illustrating a cross section of portion α in FIG. 21 in detail, which illustrates partition plate 301 between first storage room 2 and second storage room 3 and design plate 11. In partition plate 301, upper plate 306 and lower plate 7 are disposed on upper and lower sides of foamed urethane heat insulating material 8 enclosed from the back surface of the refrigerator, respectively. Further, heat radiation pipe 10 for heat radiation of a refrigerating cycle is disposed on foamed urethane heat insulating material 8 and the front surface thereof between upper plate 306 and lower plate 7. Heat radiation pipe 10 is in contact with design plate 11 with the back surface thereof being pressed by solid foamed flexible heat insulating material 9 including an expanded polystyrene and the like.
In the present structure, upper plate 306 is devised to make it difficult for the heat of heat radiation pipe 10 to intrude into the storage room. That is, upper plate 306 is provided with heat barrier 302 having a thickness smaller than that of other resin portions is provided in a depth direction of the sheet of FIG. 22, and the heat of heat radiation pipe 10 intruding into the storage room through path A in the drawing is shielded by heat barrier 302 as much as possible. With such a mechanism, the heat insulating property of the refrigerator and the storage room is enhanced, and the energy saving performance is improved.